1. Field of the Invention
The present invention relates to the field of fungicidal compositions and methods. More particularly, the present invention concerns novel fungicidal heterocyclic aromatic amides and methods involving application of fungicidally effective amounts of such compounds to the locus of a plant pathogen. The present invention also concerns methods useful in the preparation of heterocyclic aromatic amides and their fungicidal compositions.
2. Description of the Prior Art
A variety of antifungal compositions and methods are well known in the art. Antimycin, for example, has been identified as a naturally occurring substance produced by Streptomyces spp. with antibiotic properties (Barrow, C. J.; et al., Journal of Antibiotics, 1997, 50(9), 729). These substances have also been found to be effective fungicides (The Merck Index, Twelfth Edition, S. Budavari, Ed., Merck and Co., Whitehouse Station, N.J., 1996, p.120). WO 97/08135 describes acylaminosalicylic acid amides which are useful as pesticides. EP-A-O-661269 discloses substituted heterocyclic carboxylic acid amides useful as medical drugs. JP-A-7-233165 discloses antifungal dilactones having 3-hydroxypyridinecarboxyl groups with antimycotic action. The iso-butyryl, tigloyl, iso-valeryl and 2-methylbutyryl derivatives of these latter compounds are further described in the following references: Tetrahedron 1998, 54, 12745-12774; J. Antibiot. 1997, 50(7), 551; J. Antibiot. 1996, 49(7), 639; J. Antibiot. 1996, 49(12), 1226; and Tetrahedron Lett. 1998, 39, 4363-4366.
However, there has remained a need for new fungicides. The present invention provides fungicides which have a high residual activity, greater activity at lower application rates, curative activity, and a broader spectrum of efficacy.